Air conveyor for conveying articles

ABSTRACT

This invention relates to an air conveyor for conveying articles with a collar and a head arranged above that, in particular plastic bottles along a conveyor channel having two carrying strips arranged along the conveyor channel on which the articles are conveyed by suspending them from the collars, and having a head space having inclined side walls formed above the carrying strips. Air nozzles, which act upon the heads of the articles, are provided in the inclined side walls. This counteracts a tendency of the articles to become tilted or jammed together.

FIELD OF THE INVENTION

This invention relates to an air conveyor for conveying articles, havinga collar and a head above that, in particular for conveying plasticbottles.

Such an air conveyor is known from U.S. Pat. No. 5,161,919. The inclinedside walls of the head space here may prevent excessive lifting and thusalso prevents jamming of the articles between the carrying strips if thearticles are high enough. However, this positive effect must be seenagainst the fact that the air nozzles are necessarily situated beneaththe carrying strips and engage on the main body of the articles. Inaddition, this requires a bulky and cost-intensive design due to the airchannel, which extends far downward, for supplying air to the airnozzles, since cleaning of this air channel poses problems.

There is also a conveyor which is known from International Patent WO9910263, where the conveyor has carrying strips above which there is ahead space having a rectangular cross section with a filling pieceinserted into it. This filling piece is supposed to prevent an upwardmovement of the bottles. However, since the filling piece is insertedinto the head piece as a separate part, it creates gaps and/or fissuresand gradations with the walls of the head space, which is problematicalfrom a hygiene standpoint, because such regions may lead to permanentdeposits of microorganisms. However, microorganisms must be preventedabsolutely, especially in the beverage area in the case of bottles to befilled.

SUMMARY OF THE INVENTION

The object of this invention is to create an air conveyor, which willreliably prevent twisting or jamming of articles without anydisadvantages, in particular from the standpoint of hygiene and cost.

Due to the fact that the air nozzles are arranged in the inclined sidewalls of the head space, the conveyor channel or air channel may belimited to the space above the carrying strips. This results in ease ofcleaning and an inexpensive design. In addition, this arrangement of theair nozzles counteracts the development of jamming. Since the bottlesare lifted merely due to the design of the inclined side walls—withoutinserts, filling pieces or the like—this also ensures simple cleaningand an inexpensive design.

BRIEF DESCRIPTION OF THE DRAWINGS

Exemplary embodiments of the device according to this invention aredescribed and explained below on the basis of the drawings, which show:

FIG. 1 a first exemplary embodiment of an air conveyor in a perspective,schematic, partial view;

FIG. 2 a second embodiment of an air conveyor in the same view as inFIG. 1;

FIGS. 3 a through 3 b a detail from FIG. 1 in various embodiments;

FIG. 4 a schematic diagram to illustrate the functioning of the airconveyor according to this invention in breaking up log jams;

FIG. 5 a third exemplary embodiment of an air conveyor in a verticalsection.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows an air conveyor 1 with which the articles 2, namely PETplastic bottles in this case, are to be conveyed. Such bottles have acollar 3 and a head 4, and a thread is provided on the head so that aclosure can be screwed onto it. The bottle 1 is suspended by its collar3 on carrying strips 6 a and 6 b. The carrying strips 6 a and 6 b borderthe head space 5 at the bottom, i.e., they define the space in which thehead 4 of the bottle is located during conveyance.

The head space 5 has inclined side walls 8 a and 8 b which form an anglein the upper area of head space 5, in particular an acute angle. Due tothe fact that the side walls 8 a and 8 b are inclined inward, they mayserve as a stop to limit the lifting or tilting of the bottles 2. If abottle 2 is to be raised or tilted by the stream of air, by otherbottles or by other means, the upper end of head 4 will strike the sidewalls 8 a and 8 b from beneath and will thus limit the lifting ortilting movement even before the widened part of the neck of the bottlecan become jammed between the carrying strips 6 a and 6 b. This isexplained in greater detail below.

Air is blown into the head space 5 through air nozzles 9 in the form offlaps in the direction of conveyance 15, so that air acts upon thebottles 2 in the head part 4 so that they are set in motion or kept inmotion.

Above the head space 5 there is an air supply channel 10 which issupplied with air from an air pressure source, which is not described ingreater detail here. Air flows out of the air supply channel 10 throughthe nozzles 9 and thus exerts a force on the bottles 2 for theconveyance movement.

Additional optional lateral guide devices 11 are also shown in the lowerportion of FIG. 1; these serve to prevent the bottle 2 from tiltinglaterally.

The conveyor channel 7 shown here thus includes at least the head space5 with its inclined side walls 8 a, 8 b as lateral borders as well asthe carrying strips 6 a, 6 b, which border the head space at the lowerend.

Due to this design of the lateral essentially planar side walls 8 a and8 b as stops, an especially simple and inexpensive means ofmanufacturing the air conveyor is thus possible. Likewise, due to thesimple design, this yields a head space which does not have any fissuresor gaps in which microorganisms can persist, multiply and propagate.Cleaning of an air conveyor according to this invention is very simpledue to this design of the head space 5.

FIG. 2 shows another embodiment of an air conveyor 1′ according to thisinvention. Functionally identical components are provided with the samereference notation. Instead of a head space 5 having a triangular crosssection, as illustrated in FIG. 1, the head space 5 in FIG. 2 has anessentially semicircular or arc-shaped cross section. Here again, thecurved side walls 8 a and 8 b of the head space 5 form a stop to limitthe tilting and lifting of the bottle 2. Instead of an air channel 10having a rectangular cross section, an air channel 10 having a roundcross section is provided here. Any combinations of air channels 10 inFIGS. 1 and 2 with the head space cross sections from FIGS. 1, 2 and 3are possible within the scope of the present invention.

The conveyor channel 7 illustrated in FIG. 2 thus includes at least thehead space 5 with its round side walls 8 a, 8 b as well as the carryingstrips 6 a, 6 b, which border the head space at the bottom.

FIG. 3 a shows a detailed enlargement of the air conveyor 1 shown inFIG. 1, in particular its head space 5. Bottle 2 rests with its collar 3on the carrying strips 6 a and 6 b arranged at the sides, so it may moveforward or in reverse along the carrying strips, depending on thedirection of the air flow in the head space 5. Air slits, air nozzles orother orifices 9 are provided in the side walls 8 a and 8 b and aresuitable for deflecting the stream of air onto the head 4 of the bottle2. Due to the stream of air directed in this way, the bottle 2 may beset in motion. The angle 12 between the side walls 8 a and 8 b amountsto approximately 90 degrees in the exemplary embodiment shown here.

FIG. 3 a also shows that the lateral carrying strips 6 a and 6 b arearranged essentially horizontally in the direction across the airconveyor, so that the collar 3 is in surface contact with the carryingstrips 6 a and 6 b when the bottle 2 is hanging down vertically. Due tothe carrying strips, which are arranged horizontally, the position ofthe bottle 2 in which it is hanging vertically downward is stabilized inparticular.

However, FIG. 3 b shows an embodiment of this invention in which thecarrying strips 6 a and 6 b are inclined inward at the bottom.Therefore, the collar 3 is only in point contact with one of thecarrying strips 6 a and 6 b. This facilitates a free back-and-forthpendulum swinging movement of the bottle 2. Another possibleimplementation would involve a combination of the inclined carryingstrips 6 a and 6 b as illustrated in FIG. 3 b with the rounded lateralwalls 8 a and 8 b as illustrated in FIG. 2.

FIGS. 3 a and 3 b also show the dimensions, which are important for thedesign of the head space 5 as a stop for a bottle 2 which is to beconveyed. It should be pointed out that the distance between the headedge or the mouth edge of the bottle and the stop point P1 with avertical lifting movement is smaller than the length h1 of the neck ofthe bottle whereby the length h1 of the neck of the bottle here denotesthe distance between the bottom side of the collar 3 of the bottle andan imaginary peripheral line L on the neck of the bottle at the locationwhere the diameter of the neck of the bottle corresponds to the distancebetween the carrying strips 6 a, 6 b.

In addition, the distance a2 between the edge of the mouth and thelocation on the wall of the channel where the head 4 comes to a stop atpoint P2 in a tilting motion is selected so that stopping occurs at anangle at which the widening neck of the bottle has not yet come to astop on the bottom side of the carrying strips 6 a, 6 b.

FIG. 4 illustrates a particular advantage of the air conveyor accordingto this invention, which results from the fact that the air nozzles aresituated in the inclined side walls 8 a, 8 b of the head space 5, i.e.,at the height of the head 4 of the bottles 2, where the direction ofconveyance is indicated by the arrow 15. When there is a log jam ofbottles 2 in the air conveyor 1, the bottles often become fanned out asillustrated in FIG. 4. Due to deceleration of the bottles 2 with thecollar 3 on the carrying strips 6 a, 6 b, the body of the bottle 2 isdeflected forward in relation to its head part 4. This is supported inparticular by the following bottles 2, each of which presses with itsbody against the others. Due to the fact that the driving air currentacts in the area of the head 4 of the bottles, a force is exerted on thehead 4 in the direction of the arrow 13, so that this results in adirectional torque 14 on the bottles 2. This directional torque resultsin a breakup of such log jams as illustrated in FIG. 4, which is thus agreat advantage for long-term operation of such an air conveyor. If suchlog jams do not automatically break up, manual intervention isnecessary, but that is often associated with delays in production andstoppage of machines that should be operating continuously. Therefore,automatic breakup of log jams as illustrated in FIG. 4 is a greatadvantage.

This advantage is obtained in particular due to the design of the airconveyor head space 5 as a stop for the bottles 2. Due to this design asa stop, the cross section of head space 5 has a relatively small area,so that there is a definite increase in pressure upstream from the headof the bottle in the event of a log jam, because the air cannot flowfurther through the head space 5 through the narrow cross section. Thus,especially in the case of a log jam, an especially high log jamresolving force acts on the bottles due to the narrow cross section.

As an alternative to the arrangement of air nozzles 9 alone in the sidewalls 8 a, 8 b, air nozzles 9 may also be arranged in any other partbordering the head space 5. For example, this is illustrated in FIG. 2,where air nozzles are also shown in the upper part of the head space 5,which connects the curved side walls 8 a, 8 b.

In the exemplary embodiments illustrated in FIGS. 1, 2 and 3, the sidewalls 8 a and 8 b are designed in one piece or are made of one cohesivepart. In FIG. 1, for example, this is an angle having legs that form theside walls 8 a and 8 b. FIG. 2 shows a portion of a tube for limitingthe head space 5 at the top. Due to the fact that the side walls 8 a and8 b are made of a single part, any hygiene problems that might occur dueto fissures and gaps in the area of the head space are prevented.Furthermore, such a head space which contains very few angles isextremely easy to clean.

The side walls in FIG. 1 may be manufactured from a prefabricated anglesection, for example. It is also possible to manufacture the walls 8 aand 8 b separately and then weld them together in the upper area ofangle 12.

For the PET bottles, which are used especially widely in the beverageindustry, have a head diameter of 25 mm and a head height of 21 mm,including the collar (form PCO 20). The resulting geometry of the headspace 5 according to FIG. 3 a yields an optimum transport function. Theangle 12 between the side walls 8 a and 8 b amounts to 70 degrees, andthe height of the head space 5 over the horizontal supporting surface ofthe carrying strips 6 a, 6 b amounts to 45.5 mm. This results in adistance a1 of approximately 6.2 mm. Such an air conveyor 1″ is shown indetail in FIG. 5.

In the case of the air conveyor 1″ according to FIG. 5, the two inclinedside walls 8 a, 8 b are manufactured in one piece with an otherwiseplanar horizontal bottom part 16 of the air channel 10. This measurealso contributes toward low manufacturing costs and a hygienic designwithout gaps. On the bottom side, the carrying strips 6 a, 6 b aredetachably mounted by means of screws and clamps on the bottom part 16,which is at the same level as the neck collar 3 of the bottles 2.

The air nozzles 9 in this embodiment are limited to that part of thehead space 5 which is beneath the point of contact P1. This results inan absolutely smooth continuous stop surface for the bottle head 4 andreliably prevents the bottles from becoming stuck.

1. An air conveyor (1) for conveying articles (2) having a collar (3)and a head (4) above it, including plastic bottles, comprising: aconveyor channel (7) having two carrying strips (6 a, 6 b) which arearranged along the conveyor channel and on which the articles areconveyed as they hang by their collars, air nozzles (9) arranged alongthe conveyor channel to allow air to act on the articles, a head space(5) above the carrying strips for containing the head of the bottleduring conveying, the head space (5) having inclined side walls (8 a, 8b), the air nozzles (9) being provided in the inclined side walls (8 a,8 b) of the head space (5) and acting upon the heads (4) of the articlesconveying said articles (2), and wherein the angle of the inclined sidewalls are such that said side walls (8 a, 8 b) operate as stops to limitthe lifting or tilting of the articles (2).
 2. The air conveyoraccording to claim 1, wherein the inclined side walls (8 a, 8 b) of thehead space (5) with the air nozzles (9) are smooth on the inside.
 3. Theair conveyor according to claim 1, wherein the head space (5) has a roofshape.
 4. The air conveyor according to claim 1, wherein the head space(5) has a rhomboid form.
 5. The air conveyor according to claim 1,wherein the head space (5) has an arc shape.
 6. The air conveyoraccording to claim 1, and an air supply channel (10) is providedlaterally and above the head space (5) to supply blasting air to the airnozzles (9).
 7. The air conveyor according to claim 1, wherein thecarrying strips (6 a, 6 b) are arranged essentially horizontally.
 8. Theair conveyor according to claim 3, wherein the angle (12) formed betweenthe inclined side walls (8 a, 8 b) corresponds to approximately 70degrees and the height of the head space (5) corresponds toapproximately 45.5 millimeters.
 9. The air conveyor according to claim1, wherein the lower limit (16) of one of the conveyor channel (7) andthe air supply channel (10) is situated at the height of the collar (3)of the articles (2), and the carrying strips (6 a, 6 b) are mounted onthe essentially horizontal lower side of the lower limit (16).
 10. Theair conveyor according to claim 1, wherein the air nozzles (9) arearranged in the area of head space (5), which is beneath the stoppingpoint (P1) of the head (4) on the inclined side walls (8 a, 8 b).